Internal-combustion engine



E. H KIMBALL. INTERNAL COMBUSTION ENGINE.

APPLICATION FILED AUG-2,1918.

Patented May 11; 1920.

2 SHEETS-:SHEET I.

E. H. KIMBALL.

INTERNAL COMBUSTION ENGINE.

. W j 0 m" J Lm v Mn 1 4 QN yw d 2 mm n m N W. \Q\ RNVW WP 6 m vw mm \w N A \M/ m #0 I A W 7 a M 1 3 e 2 w w fi 1 k w UNITED STATES PATENT OFFICE.

EARL H. KIMBALL, OF WATERLOO, IOWA, ASS'IGNOR '10 ASSOCIATED MANUFAC- TURERS COMPANY, OF WATER/LOO, IOWA, A CORPORATION OF IOWA.

INTERNADCOMBUSTION ENGINE.

Specification of Letters Patent.

Patented May 11, 1920.

Application filed August 2, 1918. Serial No. 247,983.

To all whom it may concern Be it known that I, EARL I-I. KIMBALL, a citizen of the United States, residing at Waterloo, in the county of Blackhawk and State of Iowa, have invented certain new and useful Improvements in Inte'rnaLGombustion Engines, of which the following is a specification.

My invention relates to internal combustion engines, and has for its object the provision of simple and efficient means for holding the exhaust valve closed a part of the time so as to prevent undue cooling of the cylinder walls.

A further object is the provision of a device of this kind in which, by a slight readj ustment of the parts, the exhaust valve can be maintained open during a part of the time while the engine is running.

Further objects will appear hereinafter.

An embodiment of my invention is shown in the accompanying drawings forming a part of this specification, and in which- Figure 1 is a fragmental plan view of an internal combustion engine equipped with my device.

Fig. 2 is a fragmental elevation of the same. w

Fig. 3 is a fragmental plan view of a slightly modified form of my invention applied to a gas engine; and

Fig. 4 is a view similar to Fig. 3, except that some of the parts are shown in different positions than in Fig. 3.

Referring more particularly to the drawings, I have indicated an engine cylinder 5 and a crank shaft 6 of an internal combustion engine. The engine illustrated is of the usual stationary type, but it will be apparent from the description herein that my invention is applicable to other forms of engines. i i

The engine shown has the usual reducing gears 7 which have a ratio of two to one for timing the valves and spark of the engine. On the shaft of the larger of the. reducing gears is a cam 8, which in the present instance operates an exhaust valve of the en gine. I have not shown the cylinder broken away to expose the valves of the engine, but the ports and valves are of usual construction. I have indicated a valve stem 9 of an exhaust valve of'the engine. The stem 9 is provided with a head 10 and a compression spring 11 between the head 10 and end of the cylinder 5. The stem 9 may be the stem of the regular exhaust valve of the engine, or it may be an auxiliary exhaust valve, or any other preferred form of means for exhausting the burnt gases from the cylinder 5.

The cylinder 5 is also provided with an intake valve, which I have not shown the details of, but indicated a stem 12 as coming from such a valve. The stem 12 is provided with a head 13 and a compression spring ltbetween the head 13 and end of the cylinder 5. This may represent any usual construction.

For operating the valve stem 9, I provide a rod 15 mounted in bearings, one of which is indicated at 16 on the cylinder 5. The rod 15 is provided with a roller 17 which engages the cam 8 for causing longitudinal movement of the rod 15. The end 15 of the rod 15, opposite the roller 17, engages the bight or central portion of a substantially U-shaped lever 18 which is pivoted about a pin 19 on a lug 20, and the latter being extended from the end of the cylinder 5. Also pivoted on the pin 19, between the leg portions of the lever 18, is a lever 21 which is provided with a hardened shoulder 22. The lever 18 has a member 23 pivoted on a pin 25 on the lever 18. The member 23 also has a hardened shoulder 24 adapted to engage the shoulder 22 and lock the levers 18 and 21 together. The member 23 is provided with a lug 26 which extends sufficiently far to engage a pin 27 also in a portion of the lever 18. In order to vary the movement of the member 23 toward the ad jacent end of the lever 21, I preferably provide a screw 28 in the projection 26 which may engage the pin 27 for holding the member 23 in various positions. The member 23 is normally'held with the shoulder 24: against the shoulder 22 by a compression spring 29, and the effective strength of the spring 29 is varied by means of a screw 30 bearing on one end of the spring.

The end of the lever 21, adjacent the head 10, is provided with a screw 31 for adjusting the space between the end of such lever and said head 10. The levers 18 and 21 are provided with a coil spring 32 which tends to hold the screw 31 against the head 10 and the middle portion of the lever 18 against the end 15 of the rod 15. With the parts already described, the exhaust valve stem 9 will be operated at each revolution of the cam 8 to open and closethe exhaust valve of the stem 9.

In many forms of internal combustion engines now in use the speed of the engine is controlled by holding the exhaust valve open to prevent drawing in a new charge after the engine has exceeded a predetermined speed and until the speed of the engine has been reduced to or below such predetermined speed. In the use of hydro-carbone of low grades, such as kerosene, and the like, where air is drawn in and forced out of the cylinder when no explosions are taking place, tends to cool the walls of the cylinder so that such low grade hydrocarbons will not properly ignite. My invention is designed to provide means for holding the exhaust valve closed so that the burnt gases will be alternately compressed and expaneled while the engine is running in speeds above the desired speed. In this manner I am. enabled to maintain the cylinder walls hot and effect proper combustion of such low grade fuels.

I have shown a cam 33 which is pivoted, as at 34 on a part of the lug 20. The cam 33 is formed and mounted so that its cam surface is disposed adjacent the path of the free end of lever 23 in substantially an arc of a circle described about the axis of lever 18 when the engine is at rest or running below a predetermined speed, see Figs. 1 and WVhen the engine has exceeded such predetermined speed the cam is moved into the path of the free end of lever 23 to disenengage the shoulders 24 and 22. The member 23 may be provided with a wheel 35 for reducing the friction between the cam 33 and the end of the member 23-, if desired. When the shoulders 24 and 22 are disconnected, the lever 18 will be moved through its movements by the cam 8, but the lever 21 will not be moved, and hence the exhaust valve will be maintained closed. so that as a piston, not shown, in cylinder 5- moves in said cylinder, the exhaust gases will.- be compressed and expanded, but held in the cylin der until the shoulders 24 and 22 have been engaged again and the lever 21 operated.

' with the lever 18.

' and the latter connected through a connecting link 43 with the cam 33 so that the governor moves the collar 37 away from the gears 7, the cam 33 will be moved toward the arm 23 and move the shoulder 24 out of engagement with the shoulder 22. As soon as the speed of the engine has been reduced, the governor moves the collar 37 toward the gears 7, and thereby rocks the shaft 40 and moves the cam 33 away from the member 23, permitting the spring 29 to move said member 23 over until the shoulder 24 again engages the shoulder 22, thereby reconnecting the levers 18 and 21.

In Figs. 3 and 4 I have shown. substantially the same arrangement of parts as shown in Figs. 1 and. 2, except that on the lever 21 I have indicated a hardened shoulder 44 which is adapted to be engaged by the end of the cam 33 for holding the lever 21 at the terminal of its movement where the exhaust valve stem 9 will be held in and the exhaust valve held open. This arrangement is adapted for use when it is desired to use gasolene, or other higher grades of fuel in the engine. When it is desired to use high grades of fuel the connecting rod 42 is engaged in an opening 45 in the cam 33, and when a low grade fuel is to be used and the end of the cam 33 held so that it will not engage the shoulder 44, the connecting link 43 is moved over manually so that: it engages the hole 46 in the cam 33. When operating the engine with high grade fuel above a predetermined speed the cam 33' will be drawn over until its outer end will come in the path of the shoulder 44, but when the engine is running at slow speeds, or under a predetermined speed, the governor will hold the end of the cam 33 over toward the pin 19 and out of the path of the shoulder 44, as will be apparent from: the above.

It is sometimes desirable to change the length of the connecting rod 42' to vary the speed of the engine so that the cam will be moved. at different times toward and away from the member 23. A means for accomplishing the changing of the length of the link 43 may be a turnbuckle 47, as indicated in Fig. 3. The turnbuckle 47 is not essen tial because the speed of the engine may be varied by increasing the tension on the spring 29 and varying the screw 28, or by varying the shape of the cam 33.

While I have illustrated and described the preferred form of my invention, I do not de sire to be limited to the precise details set forth, but desire to avail myself of such variations and changes as come within the scope of the appended claims.

1. In combination, an engine exhaust valve; means tending to hold said exhaust valve closed; a lever having one end adjacent said exhaust valve; a crank shaft; means operatively associated. with said crank shaft; a lever connected with said 'means; locking means on one of said levers adapted to lock the levers 'together; and means operable by the speed of the crank shaft adapted to engage said locking means and unlock the levers when said crank shaft has exceeded a predetermined speed.

2. In combination, an engine exhaust valve; means tending to hold said exhaust valve closed; a lever adjacent said exhaust valve; a shoulder on said lever; acrank shaft; means operatively associated with said crank shaft; a lever connected with said means; a locking lever pivoted to the lastmentioned lever and engaging said shoulder; a cam adjacent said locking lever; and means operable by the speed of the engine for moving said cam into the path of said locking lever to move the latter out of engagement with said shoulder.

3. In combination, an engine exhaust valve; means tending to hold-said exhaust valve closed; a lever having one end adjacent said exhaust valve; a lever. connected with the first-mentioned lever; an engine operated'means operatively associated with the second-mentioned lever; and means for disconnecting the levers for holding the exhaust valve closed.

4. In combination, an engine exhaust valve; an engine crank shaft; a lever made up of two parts connected together with one part having a connection with said exhaust valve; means operatively associated with said crank shaft and connected with the other part of said lever; and means operable by the speed of said crank shaft for disconnecting the parts of said lever.

5. In combination, an engine exhaust valve; resilient means tending to hold said exhaust valve closed; an engine crank shaft; two levers pivoted about a common axis, one lever being operable by said crank shaft and the other lever having a connection with said exhaust valve; a lock connecting the levers together; and means connected with said lock, operable by said crank shaft and adapted to unlock said levers when the crank shaft has exceeded a predetermined speed.

6. In combination, an engine exhaust valve; resilient means tending to hold the exhaust valve closed; an engine crank shaft; two levers, one having a connection with said exhaust valve and the other being operable by the crank shaft; a connection be tween said levers; and a governor operable by the crank shaft and connected with the connection between said levers adapted to disconnect such levers for facilitating the holding of said exhaust valve closed while the crank shaft is operating.

7. In combination, an engine exhaust valve; resilient means tending to hold said valve closed; a lever; engine operated means operatively connected with said lever; a

lever operatively connected with said exhaust valve; a movable member connected with one of said levers having an engagement with the other lever locking said levers together; and a governor having a connection with said member adapted to move the latter and disconnect said levers.

8. In combination, an engine exhaust valve; resilient means tending to hold the exhaust valve closed; a lever; engine operated means operatively connected with said lever; a lever operatively connected with said exhaust valve; a movable member pivoted on one of said levers and having an engagement with the other lever locking said levers together; an arm pivoted about a fixed axis and movable toward said member; and means connected with said member for moving said arm against said member to unlock said levers. 4

9. In combination, a spring pressed ex haust valve; an engine crank shaft; two levers, one having an operative connection with the exhaust valve and the other having an operative connection with the crank shaft; a member pivoted to one of the levers and engaging the other lever; resilient means tending to hold said member in engagement with said lever as mentioned; an arm; and a governor connected with the crank shaft and said arm adapted to move the latter for moving said member to unlock said levers.

10. In combination, a spring pressed exhaust valve; an engine crank shaft; two

levers, one having an operative connection with the exhaust valve and the other having an operative connection with the crank shaft; a member pivoted to one of the levers and engaging the other lever; and governor mechanism having an operative connection with said member adapted to move the latter to disengage such member from the levers for holding the exhaust valve closed.

11. In combination, a U-shaped lever pivoted at its ends; a lever pivoted about the axis of the U-shaped lever and having one end disposed between the legs of said U- shaped lever; a spring pressed engine exhaust valve adapted for operative engagement by said second-mentioned lever; an engine crank shaft having an operative connection with the U-shaped lever; a member pivoted to the U-shaped lever and engaging the second-mentioned lever locking said levers together; and a governor having a connection with said member adapted to disengage the latter from said lever for facilitating the holding of the exhaust valve closed.

12. In combination, a U-shaped lever pivoted at its ends; a lever pivoted about the axis of the U-shaped lever and having one end disposed between the legs of said U- shaped lever; a springpressed engine exhaust valve adapted for operative engagement by said second-mentioned lever; an engine crank shaft having an operative con nection with the U-shaped lever; a member pivoted to the U-shaped lever and engaging the second-mentioned lever locking said levers together; a movable cam adjacent said member; a governor operable by said crank shaft and connected with said cam for operating the latter to move said member and disengage the latter from said lever.

13. In combination, an engine exhaust valve; an engine crank shaft; means operatively associated with said crank shaft; two levers, one having a connection with said exhaust valve and the other having a connection with said means; a member pivoted on one of said levers; two shoulders on the other of said levers, one of said shoulders beingadapted to be engaged by said member; a movable stop arranged to engage the other of said shoulders; and a governor operable by said crank shaft connected with said movable stop, the latter being adapted to be disengaged from said shoulder by said governor.

14. In combination, a crank shaft, an exhaust valve; means operable by the crank shaft; two levers pivoted at a common center, one having a portion adjacent and adapted to move the exhaust valve and the other lever being operatively'connected with said means; locking means connecting the levers; a cam having its cam surface normally substantially concentric with the pivotal center of the levers; a governor operable by the crank shaft; and an operative connection between the lever and the governor for moving the cam out of concentric relation with said pivotal center to unlock the levers.

15. An engine construction comprising two levers pivoted at a common center; a cam disposed with its cam surface substantially concentric with said common center; a shoulder on one of the levers; a member movably mounted on the other lever and resiliently held with a portion against said shoulder and a portion adjacent said cam surface; and means for moving the cam toward the portion of said member adjacent such cam for disconnecting said member from said shoulder. I I

In testimony whereof I have signed my name to this specification on this th day of July, A. D. 1918.

EARL H. KIMBALL. 

